Climatic Drivers of Karnal Bunt (Tilletia indica) in Wheat: Multiregional Assessment of Karnal Bunt Development in Wheat

Karnal bunt (Tilletia indica) affects wheat trade because even a small level of infection can result in quarantine restrictions and limit the export of grain. In this study, wheat fields across different agro-ecological regions were monitored to record disease incidence and identify locations and time periods most favorable for infection. Data on disease occurrence were analyzed alongside local climate information to understand the environmental conditions that promote disease development. The results will help guide the use of resistant wheat varieties and improve agronomic practices to manage the disease and increase crop productivity. The disease develops when the black, powdery teliospores, which can survive in soil, straw, and manure for years, germinate under suitable conditions such as moderate temperature and high soil moisture. The spores produce infectious basidiospores that attack wheat kernels during flowering, replacing the kernel’s endosperm with sori full of teliospores and producing deformed grains. During harvest, these spores are released into the field, contaminating soil, straw, and seed, and creating sources of infection for the next crop. The spread and severity of Karnal bunt depend on factors such as soil type, previous crop history, seasonal temperature, humidity, and rainfall. These findings highlight the need for integrated disease management strategies, including crop rotation, timely sowing, and careful use of fungicides, to reduce losses and control the disease.